Professor Park Jea-gun of the Department of Electronic Engineering is an expert in the field of semi-conductors, having researched it for 31 years now. His paper, “Effect of double MgO tunneling barrier on thermal stability and TMR ratio for perpendicular MTJ spin-valve with tungsten layers“, discusses the magnetic memory, which is a totally different type of memory device in the current market other than the DRAM (dynamic random-access memory) and the NAND (negative-AND) flash memory.

As semi-conductors are made into smaller models, it becomes faster as the electric power it needs gets lower, and the cost to produce the model gets lower as well. In the world of IT, the reading and writing of information should get faster as time goes. But since there are limits to the current technology in reducing the size of the semi-conductors smaller than 10 nanometers, there have been attempts to make a different type of model that could replace the DRAM technology.

Park explains about the magnetic memory being developed at HYU.

Tohoku University (THU) in Japan came up with the idea of magnetic memory from which Hanyang University (HYU), along with Samsung Electronics, SK Hynix, and the Korean government invested 40 billion won to develop a semi-conductor research facility. There are only two other facilities that are able to produce such novel technology, which are in the United States and Belgium. Since the idea provided by THU was not a fully developed one, Park changed the material needed to produce it into tungsten. The result has been quite successful in that it can now be activated even at 400 degrees while what was proposed at THU could only hold up to 300 degrees.

The original memory types used to have what is called a capacitor. By charging electrons in it or discharging it, the digital signal becomes 1 and 0 respectively. As for the magnetic memory, it has two magnetic layers. One has fixed electron while the other has a free one. In between the two layers, there is an insulation layer. The fixed electron always flows in the same direction while the free electron flows in the direction of the electric power. Once the two electrons are flowing in the same direction, more electric power flows and it has lower resistance, which reads data 0 state while the opposite means data 1. In other words, it can be said that the way to produce D0 and D1 is different from the original type in charging the electrons and discharging them, or by letting the electrons flow in either the same or opposite direction.

The sizes of DRAM and NAND would be difficult to get smaller than 10 nm. (Photo courtesy of Park)

Evidently, there are advantages to the magnetic memory in that the changes in the direction of flow of electrons are very fast. Charging and discharging capacitors take much longer and consumes more electric power as well. In addition, the capacitor needs a certain surface area, while this new form of memory gets faster as the size gets smaller. It can be said that this nano structure element is an absolute must when it comes to scaling down the size of memory storage.

It is believed that this technology would be necessary in developing the internet of things, or IOT technology, once it has been stabilized. Magnetic memory has now been successfully installed onto a System on Chip (SoC). This technology is crucial for IOT technology, and it is predicted that the memory technology at this stage will not be in use by 2022 to 2025.

Park wishes that his technology would make people's lives more easier.

Park believes that by developing the original technology and being credited for the paper would eventually be a huge contribution to the Korean society where the semi-conductor industry accounts for about 5% of Korean GDP. Through his technology, Park aims to make people feel the comfort of advanced technology when it comes to our daily lives and the information-oriented era.